The objective of the original proposal was to determine how neurons make specific synaptic connections. In particular the pattern of connections made by sensory neurons of crickets was to be examined morphologically and physiologically. Our hope was to demostrate some of the basic rules by which this simple nervous system is constructed. The first part of the project, now nearing completion, has concentrated on describing the anatomy of the cercal afferent projection. We developed rapid methods for straining single sensory neuronn and applied it to a study of this projection. The essence of the result is that a somatotopic map exists between the peripheral and central nervous system. More important this orderly projection is consistent with positional information models for the production of patterns in the insect epidermis (e.g. French et al.). Thus it now appears that a basic set of rules for the production of orderly patterns on the insect body apply to insect sensory neurons and whatever the mechanism is it leads to the production of orderly projections between the peripheral and central nervous system. The results have important consequences for our ideas concerning the production of specific synaptic connections between peripheral and central neurons. Previous work on the giant neurons which receive input from the cercal afferents has described many of these first order interneurons in detail. The anatomy of the cercal afferent projection and the anatomy of these giant neurons suggests that the response properties of an interneuron are a direct consequence of the anatomical organization.